びまん性血管損傷 磁化率強調画像を用いた重症頭部外傷での収束性出血

INTRODUCTION:Susceptibility-weighted image (SWI) is one of the most sensitive methods for detect microbleeding and useful for evaluation of traumatic brain damage. The purpose of this study is to delineate the characteristics and importance of supratentorial deep white matter hemorrhages detected by SWI in cases of traumatic brain damage. METHODS:Twenty-one consecutive cases with severe traumatic head injury were included in the current study. MRI examinations were made within 1 month after injury. We evaluated the degree and distribution of the supratentorial hemorrhages on SWI retrospectively. We classified the degree of bleeding into four grades: "small hemorrhage," "single bead-like hemorrhage," "convergent-type hemorrhage," and "massive hemorrhage." We then correlated the degree and distribution of the hemorrhage to clinical outcomes. We also evaluated the apparent diffusion coefficient (ADC) image of lobes with "convergent-type hemorrhage." RESULTS:Existence of "massive hemorrhage" correlated with a poor outcome, that is, worse than "severely disabled" on the Glasgow Outcome Scale. The number of lobes affected by "convergent-type hemorrhage" also correlated with poor outcome. There were 45 lobes with "convergent-type hemorrhage" and 27 of them showed increased diffusivity on ADC images. CONCLUSION:Supratentorial massive hemorrhages and supratentorial convergent-type multiple hemorrhages were associated with poor prognosis after traumatic brain injury. The increased diffusivity in lobes with convergent-type hemorrhages may indicate that congestion of the proximal medullary vein may play some role for these hemorrhages.博士（医学）・甲第594号・平成25年3月15日© Springer International Publishing AG,201

Semi-metallic bulk generated spin-orbit torques in disordered topological insulator

Spin-orbit torque (SOT) induced by the transfer of orbital angular momentum from a lattice to a spin system offers an efficient route for manipulating spin-based devices. Among various potential candidates, three-dimensional topological insulators (TIs) with inherently strong spin-orbit coupling promise to be a powerful source of SOTs. While the huge SOTs observed in ferromagnet (FM)/TI bilayers are generally claimed to be of topological surface states (TSS) nature, the contributions from the surface and bulk states in realistic systems are undistinguishable, rendering the underlying physics elusive. Here, we provide direct evidence that the bulk spin-Hall effect dominates the SOTs generated by disordered TIs. We show that sizable SOTs with clear bulk feature are generated by bismuth antimonides, in which the semi-metallic bulk state intermediately couples to the surface states. From our analysis based on a drift diffusion approach, the lower limit of spin Hall conductivity turns out to be $0.66 \times 10 ^{5} (\hbar/2e)$ $\Omega$$^{-1}$m$^{-1}$, which is comparable to the reported values against the general belief in TSS origin. Furthermore, the complementary results of SOT generation and Gilbert damping enhancement suggest an essential role of band bending near the FM/TI interface upon modifying the relative magnitude of the real and imaginary parts of spin mixing conductance. Together with the bulk spin Hall effect, our finding may alter the landscape of the field of spin-orbitronics in TI based systems and develop new applications such as SOT transistors

Novel method for detection of pancreatic beta cell death using cell-free DNA

In people with type１ diabetes（T１D）, biomarkers that can sensitively and quantitatively evaluate injury of pancreatic beta cell are required in order to predict the onset of the disease at an early stage and to provide interventions to prevent the progression of the disease. We developed a new method for quantifying pancreatic beta cell-derived insulin DNA in circulation that combines bisulfite conversion and Amplification Refractory Mutation System（ARMS）PCR, which can be performed using a conventional real-time PCR system. We applied this method to T１D patients and healthy adults, both could be detected in about ３０％ of cases. The results in healthy adults indicate that this method may have sensitivity to detect the turnover of pancreatic beta cells at physiological conditions. In post-onset T１D patients, there were many negatives because the amount of residual pancreatic beta cells was extremely small. However, in some cases with a short duration of the disease, pancreatic beta cell-derived insulin DNA was detected in negative correlation between the duration of the disease, that suggested the residual pancreatic beta cells continue to be slowly destroyed. It was demonstrated that the time course of pathophysiology in T１D could be understood using this method

Suspected Low-Pressure Hydrocephalus Caused by Spinal Drainage after Subarachnoid Hemorrhage

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Use of a Contest Format for Objective Assessment of Microsurgical Technique: An Observational Study

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